Subaru has dropped several hints that a high-performance STI version of its BRZ coupe is in the works, including one very big hint even before the BRZ made its debut. Then, just a few weeks ago, a prototype wearing STI badges was spotted running some laps on Germany’s Nürburgring, confirming the car's existence.

The prototype revealed that the BRZ STI will feature popular performance mods such as a large rear wing, aerodynamic body kit, lowered suspension, large alloy wheels and a sports exhaust. What it didn’t reveal, however, is whether the car’s engine has been fitted with a turbocharger or other means of forced induction, something past STI models have traditionally featured.

According to reports overseas, the BRZ STI, which will be revealed next spring, will forgo a turbocharger due to a lack of space under the hood. Despite this, peak output should still rise from the BRZ’s 150kW rating to somewhere around 165-172kW in the BRZ STI thanks to changes to the exhaust system and variable valve timing.

This ties in with previous comments from Subaru that there was no space for an intercooler and its required piping in the BRZ’s engine bay. Furthermore, the addition of a turbocharger would go against the purist sports car philosophy Subaru engineer’s had originally envisioned for the BRZ. A supercharger is also said to have been ruled out due to a loss in the car’s fuel economy, though it's more likely Subaru doesn't want the BRZ STI encroaching on the performance of its next-generation WRX.

The good news is that the relatively mild mods being applied to the BRZ STI should equate to a relatively low price rise. And the BRZ, along with its Scion FR-S twin, is already one of the most fun cars you can buy, so a little extra power, sharper handling and an affordable sticker should make the BRZ STI one very enticing package.